Information recording device, information reproducing device, information recording medium, method, and computer program

ABSTRACT

An apparatus for recording additional information hard to analyze in an information recording medium, a reproducer, a recording medium, a method, and a computer program for the same are provided. Bit values set at a plurality of DC control bit information setting positions set in a recording frame are decided based on constituent bit information of additional data, and additional data such as key information used for decoding contents is recorded in the information recording medium. In the reproducer, the additional data constituent bit information can be acquired by detecting the bit position set at a selected DC control bit storage position in the additional data-associated recording frame. With the configuration, it is possible to embed additional information such as key information used for decoding contents, key production information, contents reproduction control information, and copying control information with a format hard to analyze and also to accurately read out for data reproduction.

TECHNICAL FIELD

The present invention relates to an information recorder/processor, aninformation reproducer, an information recording medium, an informationrecording method, and a computer program for the same. Morespecifically, this invention relates to an informationrecorder/processor capable of recording in an information recordingmedium for recording therein contents such as video data and musicaldata, various types of additional information such as key informationused for decoding various contents, contents reproduction controlinformation, and copying control information with a format disablinganalysis by setting DC (Digital Coding) control bit and also enablingreading the recorded information, an information reproducer, aninformation recording medium, an information recording method, and acomputer program for the same.

BACKGROUND ART

When recording data such as musical data or video data as digital datain a recording medium, recording is performed according to aprespecified record format. For instance, error detection/correctioncode is added to original data to be recorded, and the data is coded toa format corresponding to a specific data recording/reproducingprocessing for recording.

Recently a system making it possible to record and reproduce informationby using a blue laser as an information recording medium enabling highdensity information recording has been developed. In the informationrecording processing with the blue laser, basically demodulation isperformed to demodulate 2-bit data to 3-bit data.

Contents to be stored in the information recording medium as describedabove include, for instance, moving pictures and musical data. Thedistribution rights of the contents such as musical data or video dataare generally owned by the producers or distributors. Therefore, whendistributing the contents, specific restrictions are applied toutilization of the data. In other words, utilization of the contents isgenerally allowed only to authorized users to inhibit unauthorizedcopies of the contents.

A large capacity recording medium such as a recording medium based on ablue laser recording system enabling high capacity recording can recordtherein data for one to several moving pictures in one recording medium.In association with the possibility of easily recording contents asdigital information, the problem of illegal copies occurs everywhere,and the social problem of infringement of interests of copyright ownersand distribution right owners has become serious. In the currentsituation as described above, prevention of illegal copies andprotection of interests of copyright owners and distribution rightowners are now extremely important problems.

To prevent illegal utilization of contents as described above, theconfiguration is proposed in which contents to be stored in aninformation recording medium is stored as encrypted contents and at thesame time encryption key information configured to be used inutilization of the encrypted contents, information required forgeneration of an encryption key, or other various types of controlinformation such as those used for reproduction and copying of contentsare stored as secret information in the information recording medium. Inthis configuration, the reproduction processing program installed in auser's reproducer reads the secret information such as a keycorresponding to contents to be reproduced, decodes the contentsaccording to the read secret information as described above, or allowsutilization of contents according to the reproduction controlinformation.

As an example of the related technique for burying the secretinformation, for instance, Patent document 1 discloses the configurationin which specific data is buried by applying a connection bit (a marginbit) for EMF modulated data. Patent document 2 discloses theconfiguration in which a plurality of conversion tables are applied tomodulation, data relating to the conversion tables applied to modulationis extracted in reproduction, and additional data is acquired based onthe extracted data.

However, when the information indicating where the encryption key orcontrol information is stored in an information recording medium is onceacquired by a user or an illegal contents user, leakage or falsificationof additional information disadvantageously becomes possible. Forinstance, there occur such problems as falsification of reproductioncontrol information or copying control information or leakage of keyinformation. Once the encryption key is leaked or the controlinformation is falsified, utilization of contents based on authorizedcontents utilization right becomes completely impossible, which disablessufficient protection of copyright and utilization right for contents.

[Patent document 1] Japanese Patent Laid-open No. 2003-45128

[Patent document 2] Japanese Patent Laid-open No. 2002-367282

DISCLOSURE OF INVENTION

The present invention was made in the light of the problems as describedabove, and it is a desire of the present invention to provide aninformation recorder/processor, an information reproducer, aninformation recording medium, an information recording method, and acomputer program enabling recording of various types of additionalinformation such as an encryption key stored with contents in arecording medium, an encryption key production information, contentsreproduction control information, contents copying control informationand other contents attribute information in an information recordingmedium with a format which can not be read in the general data readprocessing to prevent the recorded information from being illegally readout.

More specifically, it is a desire of the present invention to provide aninformation recorder/processor, an information reproducer, aninformation recording medium, an information recording method, and acomputer program enabling recording of additional information withhigher difficulty in deciphering by recording a DC control bit generallyset in a recording frame as a data recording unit for DSV (Digital SumValue) control as a bit value decided based on additional informationsuch as an encryption key.

The present invention provides, in a first aspect thereof, aninformation recorder/processor including a modulated data producingsection for producing a modulated recording frame as a recording unitdata by setting a DC control bit to data to be recorded and executingmodulation of the data, and a DC control bit specifying section fordeciding a bit value set at a DC additional data-associated control bitposition selected from a plurality of DC control bit setting positionsincluded in an additional data-associated recording frame based onconstituent bit information of the additional data, and the modulateddata producing section sets a bit value of the additionaldata-associated DC control bit position in the additionaldata-associated recording frame in accordance with the instructionspecified by the DC control bit specifying section.

In an information recorder/processor according to an embodiment of thepresent invention, the DC control bit specifying section sets aplurality of DC control bit positions included in the additionaldata-associated recording frame as additional data-associated DC controlbit positions, and decides a plurality of bit values at a plurality ofadditional data-associated DC control bit positions based on theconstituent bit information of the additional data.

In an information recorder/processor according to an embodiment of thepresent invention, the DC control bit specifying section decides one bitinformation selected from a plurality of different DC controlinformation corresponding to one additional data constituent bitinformation as bit information to be set at the additionaldata-associated DC control bit position, and decides, when the bitinformation based on the DSV measurement set at the additionaldata-associated DC control bit position is identical to the DC controlbit information associated to the additional data constituent bitinformation to be set, bit information different from that based on theDSV measurement as bit information set at the additional data-associatedDC control bit position.

In an information recorder/processor according to an embodiment of thepresent invention, the DC control bit specifying section decides one bitinformation selected from a plurality of different DC control bitinformation corresponding to constituent bit information of oneadditional data as bit information to be set at the additionaldata-associated DC control bit position, and decides bit informationwith a smallest number of bits changed from the bit information based onthe DSV measurement at the additional data-associated DC control bitposition as bit information to be set at the additional data-associatedDC control bit position.

Furthermore, in an information recorder/processor according to anembodiment of the present invention, the DC control bit specifyingsection decides different bit information as bit information to be setat the additional data-associated DC control bit position according tosingle constituent bit of 0 or 1 in the additional data.

In an information recorder/processor according to an embodiment of thepresent invention, the DC control bit specifying section decidesdifferent bit information as bit information to be set at the additionaldata-associated DC control bit position according to a plurality ofconstituent bit arrays in the additional data.

Furthermore, in an embodiment of the present invention, the informationrecorder/processor sets the additional data as constituent informationfor at least one of encryption key information, encryption keyproduction information, contents reproduction control information, orcontents copying control information for contents to be stored in theinformation recording medium.

In an information recorder/processor according to an embodiment of thepresent invention, the modulated data producing section executes datamodulation satisfying RLL (1, 7) as the run length limited to produce amodulated recording frame.

In an information recorder/processor according to the present invention,the modulated data producing section executes modulated recording frameproduction including a step of converting 2-bit information to 3-bitinformation.

The present invention provides, in a second aspect, an informationreproducer for executing reproduction of information stored in aninformation recording medium, and the information reproducer includes adata demodulating section for executing demodulation of data read outfrom the information recording medium; and an additional data decodingsection for analyzing bit information set at an additionaldata-associated DC control bit position included in an additionaldata-associated recording frame and acquiring additional dataconstituent bit information based on a result of the analysis.

Furthermore, in an information reproducer according to an embodiment ofthe present invention, the additional data decoding section analyzes aplurality of DC control bits included in the additional data-associatedrecording frame, and acquires bit information previously associated to abit array to be acquired as additional data constituent bit informationaccording to a result of the analysis.

Furthermore, in an information reproducer according to an embodiment ofthe present invention, the additional data decoding section acquires asingle constituent bit of 0 or 1 in the additional data based on bitinformation set at the additional data-associated DC control bitposition set in one recording frame.

In an information reproducer according to an embodiment of the presentinvention, the additional data decoding section acquires a plurality ofconstituent bit information in the additional data based on bitinformation set at the additional data-associated DC control bitpositions set in one recording frame.

Further in an embodiment of the present invention, the informationreproducer produces at least one of encryption key information,encryption key production information, contents reproduction controlinformation, or contents copying control information for contents to bestored in the information recording medium based on the acquiredadditional data constituent bit information.

The present invention provides, in a third aspect thereof, aninformation recording medium storing therein recorded data based on arecording frame with a DC control bit based on DSV control; and recordeddata based on recording frames associated to additional data with a bitvalue decided based on constituent bit information of additional dataset at a plurality of DC control bit positions.

In an information recording medium according to an embodiment of thepresent invention, the bit information stored at a plurality ofadditional data-associated DC control bit positions in a recording frameassociated with the additional data is different from bit informationbased on the DSV measurement.

In an information recording medium according to an embodiment of thepresent invention, bit information associated to additional data set inone additional data-associated recording frame indicates a singleconstituent bit of 0 or 1 associated to additional data set in theadditional data-associated recording frame.

Furthermore, in an information recording medium according to anembodiment of the present invention, bit information associated toadditional data set in a recording frame associated to one additionaldata is information indicating a plurality of constituent bits in theadditional data.

Furthermore, the information recording medium according to an embodimentof the present invention stores therein the additional data asconstituent information for at least any one of encryption keyinformation, encryption key production information, contentsreproduction control information, and contents copying controlinformation for contents to be stored in the information recordingmedium.

The information recording medium according to an embodiment of thepresent invention stores therein data based on modulated recording frameproduced by executing data conversion satisfying RLL (1, 7) as the runlength limited.

Furthermore the information recording medium according to an embodimentof the present invention records therein data based on a modulatedrecording frame produced by converting 2-bit information to 3-bitinformation.

The present invention provides, in a fourth aspect thereof, aninformation recording/processing method including the step of: decidinga bit value to be set at an additional data-associated DC control bitposition selected from a plurality of DC control bit setting positionsincluded in an additional data-associated recording frame based onconstituent bit information for the additional data; and producing amodulated recording frame as a record unit by setting the bit valuedecided in the DC control bit specifying step at the additionaldata-associated DC control bit position included in the additionaldata-associated recording frame and executing data modulation.

In an information recording/processing method according to an embodimentof the present invention, a plurality of DC control bit positionsincluded in the additional data-associated recording frame are set as DCcontrol bit positions associated to the additional data in the DCcontrol bit specifying step, and the method further includes a step ofdeciding a plurality of bit values of the additional data-associated DCcontrol bit positions based on constituent bit information in theadditional data.

An information recording/processing method according to an embodiment ofthe present invention, the DC control bit specifying step includes thestep of deciding one bit information selected from a plurality ofdifferent DC control bit information associated to constituent bitinformation of additional data as bit information to be set at a DCcontrol bit position associated to the additional data, and in thisstep, when the bit information based on DSV measurement at theadditional data-associated DC control bit position is identical to theadditional data-associated DC control bit information associated toadditional data constituent bit information to be set, bit informationdifferent to the bit information based on the DSV measurement is decidedas bit information to be set at the additional data-associated DCcontrol bit position.

In an information recording/processing method according to an embodimentof the present invention, the DC control bit specifying step furtherincludes the step of: deciding one bit information selected from aplurality of different DC control bit information associated toconstituent bit information of one additional data as bit information tobe set at the additional data-associated control bit position; anddeciding bit information with a smallest number of bits changed from thebit information based on DSV measurement at the additionaldata-associated DC control bit position as bit information to be set atthe additional data-associated DC control bit position.

In an information recording/processing method according to an embodimentof the present invention, different bit information is decided in the DCcontrol bit specifying step as bit information to be set at theadditional data-associated DC control bit position according to a singleconstituent bit of 0 or 1 in the additional data.

Furthermore, in an information recording/processing method according toan embodiment of the present invention, different bit information isdecided as bit information to be set at the additional data-associatedDC control bit position according to a plurality of additional dataconstituent bit arrays in the DC control bit specifying step.

The information recording/processing method according to an embodimentof the present invention further includes the step of setting theadditional data as constituent information for at least any one ofencryption key information, encryption key production information,contents reproduction control information, and contents copying controlinformation for the contents to be stored in the information recordingmedium.

In an information recording/processing method according to an embodimentof the present invention, a modulated recording frame is produced byexecuting data modulation satisfying RLL (1, 7) as the run lengthlimited in the modulated data producing step.

In an information recording/processing method according to an embodimentof the present invention, a modulated recording frame is produced byconverting 2-bit information to 3-bit information in the modulated dataproducing step.

The present invention provides, in a fifth aspect thereof, aninformation reproducing method for executing reproduction of informationstored in an information recording medium, and the method includes thestep of: demodulating data read out from an information recordingmedium; and decoding an additional data by analyzing bit information atan additional data-associated DC control bit position included in theadditional data-associated recording frame and acquiring additional dataconstituent bit information based on a result of the analysis.

In an information reproducing method according to the present invention,the additional data decoding step includes the step of analyzing aplurality of DC control bits included in the additional data-associatedrecording frame and acquiring bit information previously associated to abit array to be acquired as additional data constituent bit informationbased on a result of the analysis.

Furthermore, in an information reproducing method according to thepresent invention, a single constituent bit of 0 or 1 in the additionaldata is acquired based on bit information set at the additionaldata-associated DC control bit position set in one recording frame inthe additional data decoding step.

In an information reproducing method according to an embodiment of thepresent invention, a plurality of constituent bit information of theadditional data is acquired based on bit information set at theadditional data-associated DC control bit position set in one recordingframe in the additional data decoding step.

The information reproducing method according to an embodiment of thepresent invention further includes the step of executing production ofat least any of encryption key information, encryption key productioninformation, contents reproduction control information, and contentscopying control information for the contents to be stored in theinformation recording medium based on the acquired additional dataconstituent bit information.

The present invention provides, in a sixth aspect thereof, a computerprogram for executing processing for recording information, and thecomputer program includes the steps of: deciding a bit value to be setan additional data-associated DC control bit position selected from aplurality of DC control bit setting positions included in an additionaldata-associated recording frame based on constituent bit information forthe additional data; and producing a modulated recording frame as arecord unit by setting the bit value decided in the DC control bitspecifying step at the additional data-associated DC control bitposition in the additional data-associated recording frame and executingdata modulation.

The present invention provides, in a seventh aspect thereof, a computerprogram for executing reproduction of information stored in aninformation recording medium, and the computer program includes thesteps of demodulating data read out from an information recordingmedium; and decoding an additional data by analyzing setup bitinformation of additional data-associated DC control bit positionincluded in an additional data-associated recording frame and acquiringadditional data constituent bit information based on a result of theanalysis.

The computer program according to the present invention is installed ina computer system capable of executing various types of program code,and can be provided in the state where the program is stored in acomputer-readable recording medium such as a CD, and FD, or an MO, orcan be provided from a communication medium such as a communicationnetwork. By providing the program in the computer-readable state, aprogram corresponding to each program is realized in the computersystem.

Other and further objects, features, and advantages of the presentinvention will be clarified by referring to detailed descriptions ofpreferred embodiments of the present invention and to the appendeddrawings. The “system” as used herein logically indicates a collectionof a plurality of devices, and the devices constituting the system arenot always provided within a housing.

With the configuration according to the present invention, in arecorder/processor for recording additional data in a recording mediumand processing various types of additional data such as key information,key production information, contents reproduction control information,copying control information applied to decoding of contents, bit valuesof a plurality of DC control bit information setting positions to be setin a recording frame associated to additional data is decided byconstituent bit of the additional data, which is buried in an additionaldata burying area, and in the reproducer, the additional constituent bitinformation can be acquired by detecting the bit value at a specified DCcontrol bit position in a recording frame associated to the additionaldata. With the configuration as described above, the configuration canbe realized in which additional information such as key information, keyproduction information, contents reproduction control information, andcopying control information can be buried with a format substantiallydisabling analysis of the additional data, and also can accurately beread out in reproduction.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view illustrating configuration of an informationrecorder/processor according to the present invention;

FIGS. 2(a) to 2(d) are views (1) illustrating details of processing in amodulated data producing section in the information recorder/processoraccording to the present invention;

FIGS. 3(d) to 3(h) are views (2) illustrating details of processing in amodulated data producing section in the information recorder/processoraccording to the present invention;

FIG. 4 is a view illustrating details of data configuration in aconversion table applied to modulation processing in the informationrecorder/processor according to the present invention;

FIG. 5 is a view illustrating processing executed in a record signalprocessing circuit in the information recorder/processor according tothe present invention;

FIGS. 6(A) and 6(B) are views illustrating detailed configuration of aBIS block and a BIS cluster;

FIG. 7 is a view illustrating an ECC cluster set based on an LDC clusterand a BIS cluster;

FIG. 8 is a view illustrating an ECC cluster, a DC control bitadjustment frame associated to additional data, and a DC control bitadjustment recording frame associated to the additional data;

FIG. 9 is a view illustrating an example (1) of correspondence betweenconstituent bits of additional data and DC control bits in the presentinvention;

FIG. 10 is a view illustrating an example (2) of correspondence betweenconstituent bits of additional data and DC control bits in the presentinvention;

FIGS. 11(a) and 11(b) are views illustrating an example of processingfor setting DC control bits based on additional data executed in theinformation recorder/processor according to the present invention;

FIGS. 12(a) and 12(b) are views illustrating another example ofprocessing for setting DC control bits based on additional data executedin the information recorder/processor according to the presentinvention;

FIG. 13 is a flow chart (1) for illustrating a sequence of additionaldata recording processing executed in the information recorder/processoraccording to the present invention;

FIG. 14 is a flow chart (2) for illustrating a sequence of additionaldata recording processing executed in the information recorder/processoraccording to the present invention;

FIG. 15 is a view illustrating an information reproducer according tothe present invention; and

FIG. 16 is a flow chart for illustrating a sequence of additional datarecording processing executed in the information reproducer according tothe present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The information recorder/processor, the information reproducer, theinformation recording medium, the information recording method, and thecomputer program for the same according to the present invention aredescribed below in detail with reference to the drawings.

At first, a configuration and processing of the informationrecorder/processor according to the present invention are described withreference to FIG. 1. The information recorder/processor described hereincovers a mastering device as a manufacturing device for what is called amaster disc, as well as a device including an information recordingmedium drive such as a DVD recorder/player and a PC usable for regularusers. Namely, an information processor capable of writing data not onlyon a master disc but also on various recordable and rewritableinformation recording media is covered.

The configuration and processing of the information recorder/processorare described with reference to FIG. 1. The informationrecorder/processor includes an information recording medium 101 capableof recording data, a pick-up 102 for outputting a data-recording signalto the information recording medium 101, a spindle motor 103 for drivingthe information recording medium 101, a servo circuit 104 forcontrolling the pick-up 102 and the spindle motor 103, an additionaldata error correcting/coding section 105, a main data errorcorrecting/coding section 106, an additional data recording area controlsection 107, a switch 108, a modulated data producing section 109, a DCcontrol bit specifying unit 110, a record signal processing circuit 111,a DSV (Digital Sum Variation) measuring section 112, and a DSV-based DCcontrol bit setting section.

A content data recorded on the information recording medium 101 is, forinstance, a coded content data inputted in the main data errorcorrecting/coding section 106 as a main data. The main data errorcorrecting/coding section 106 executes a coding processing by producingand adding an error correcting code to the inputted data.

A modulating processing is then executed in the modulated data producingsection 109. The information recorder/processor according to the presentinvention executes a modulation, for instance, based on the RLL (1, 7)modulating method on the basis of a modulation from 2-bit data to 3-bitdata.

The modulation based on the RLL (1, 7) modulating method is a dataconverting method using a modulated data according to the RLL (1, 7) runlength limited where the number of successive [0] is at least one and atmost seven based on the modulated bit. This converting method uses aconversion table. A specific example of using the conversion table willbe described later.

Based on the modulation data, a recording unit called a recording framefor which a synchronization signal is set up is produced and recorded inthe information recording medium 101 via the record signal processingcircuit 111.

During the modulating processing, a DC control bit inserting processingof selecting and inserting either [0] or [1] for a DC control bit isexecuted so that an absolute value of the DSV (Digital Sum Variation)becomes smaller to execute the modulating processing for the data frameinserted with the DC control bit.

The DSV is an index for the DC balance of an NRZI conversion signalproduced as a record signal for the information recording medium. Morespecifically, assuming that a value accumulated with the bit [0] in arecording bit series (NRZI conversion signal) regarded as [−1] and thebit [1] as [+1] is DSV, either [0] or [1] for a DC control bit isselected and inserted so as to minimize a deviation of the DSV from 0,and then the modulating processing is executed. The NRZI processing willbe described later in detail.

However, with the present invention, for the recording area (recordingframe) of an additional data such as an encryption key, the DC controlbit is not partially selected based on the DSV for the bit set-up but avalue selected based on a constituent bit of the additional data is setas a DC control bit. This processing will be described later.

A modulated data producing processing executed in the modulated dataproducing section 109 is described in detail with reference to FIGS.2(a) to 2(d) and FIGS. 3(d) and 3(h).

The recorded data includes, as shown in FIG. 2(a), a user data 201 and auser control data (UCD) 211. The user data 201 includes an entity dataof a reproduced data such as a content data, and the user control data211 includes various control data such as reproduction controllinginformation and copy-controlling information.

The user data 201 is set based on a unit of 32 frames each of whichincludes 2048-byte data and 4-byte parity. The user control data 211 isconfigured with 32 units of 18-byte data.

A data block 202 is formed based on the user data 201 with 32frames×(2048+4). The data block 202 has an array of 304 columns×216rows. A unit of 1 column×1 row stores 1 byte (8 bits) data.

For the data block 202, an LDC block 203 is produced as a data blockwith 32-row parity added to each column, and an interleaving processingto the LDC block 203 produces an LDC cluster 204 with 152 columns×496rows.

In the meantime, after the user control data 211 is combined with aphysical address data 221 with 16×9 bytes to produce an access block 212with 24 columns×30 rows, a BIS block 213 is produced as a data blockwith 32-row parity added to each column for the access block 212, and aninterleaving processing to the BIS block 213 produces a BIS cluster 214with 3 columns×496 rows.

FIG. 3(d) shows a data similar to FIG. 2(d), namely the LDC cluster 204with 152 columns×496 rows produced based on the user data 201 and theBIS cluster 214 with 3 columns×496 rows produced based on the usercontrol data 211.

The LDC cluster 204 with 152 columns×496 rows is, as shown in FIG. 3(d),divided into four parts (I to IV) based on the unit of 32 columns, theBIS cluster 214 with 3 columns×496 rows is divided into three parts (ito iii) based on the unit of 1 column, and each parts of these clustersare combined alternately to produce an ECC cluster 231 with 155columns×496 rows as shown in FIG. 3(e).

Further, the ECC cluster 231 is set as a cluster 232 divided into 28parts denoted by reference numerals 0 to 27 in FIG. 3(f). Only part 0has 25 bits, and all the other parts have 45 bits each. The bit rateshown in FIG. 3(f) means a bit rate per row.

Furthermore, as shown in FIG. 3(g), a Sync bit with 20 bits is set, anda DC control bit with 1 bit is set between each of parts 0 to 27 in FIG.3(f).

As a result of this, a physical cluster 233 with [1240+20 (Sync)+(1 DCcontrol×28)=1288]×496 rows is set. Each row in the physical cluster 233is assumed to be a recording frame 234 as a unit of modulated dataproducing processing.

The DC control bit is an index for a DC balance of the NRZI conversionsignal produced as a record signal for the information recording medium.More specifically, assuming that a value accumulated with the bit [0] ina recording bit series (NRZI conversion signal) regarded as [−1] and thebit [1] as [+1] is DSV, either [0] or [1] for the DC control bit isselected and inserted so as to minimize the deviation of the DSV from 0.

However, as described above, with the present invention, for therecording area of the additional data, the DC control bit is notselected according to the rule described above for the bit set-up, buteither [0] or [1] for the DC control bit is selected and inserted basedon the constituent bit of the additional data is set as a DC controlbit. This processing will be described later.

Returning to FIG. 3(d) to 3(h), the explanation of the modulated dataproducing processing continues. To the recording frame 234 with 1288-bitdata, a modulating processing to convert 2-bit data into 3-bit data isexecuted. In the data conversion, data conversion using a modulated dataaccording to the RLL (1, 7) run length limited where the number ofsuccessive [0] is at least one and at most seven is executed to producea modulation recording frame 235.

The modulation recording frame 235 is configured with 30 channel bits ofSync channel bit as the modulated data bit and (1288−20 syncbit)×2/3=1902 channel bit, totaling 1932-channel bit.

A conversion table is used for the data converting processing from 2-bitdata to 3-bit data according to the RLL (1, 7) run length limited. Aspecific example of the conversion table is shown in FIG. 4.

As shown in FIG. 4, the conversion table is configured as a tablecorrelating the modulated data bits with each input bit. For instance,when the input data is [00000000], the modulated data bit is[010100100100]. When the input data is [11], the modulated data bit is[000] if the preceding modulated data bit is [xx1], or [101] if thepreceding modulated data bit is [xx0].

The modulated data bit according to the RLL (1, 7) run length limited isproduced by executing the data conversion from 2-bit data to 3-bit dataaccording to the table.

Returning to FIG. 1, the explanation of the configuration and processingof the information recorder/processor according to the present inventioncontinues. The modulated data producing processing described withreference to FIGS. 2(a) to 2(d) to FIG. 4 is executed in the modulateddata producing section 109 in FIG. 1, and the record signal based on theproduced modulated data is produced in the record signal processingcircuit 111.

The record signal processing circuit 111 produces an NRZI (Non Return toZero Inverted) signal for inverting the plus and minus of a pulseaccording to the value [0] or [1] of the modulated data produced by themodulated data producing section 109, and records the same on theinformation recording medium 101 as a record signal.

A configuration of the NRZI production as a record signal executed bythe record signal processing circuit 111 is described with reference toFIG. 5. The channel bit as a modulated data bit outputted from themodulated data producing section 109 is inputted to the record signalprocessing circuit 111 including an NRZ converting unit 121, anexclusive OR (XOR) 122, and a Delaying unit 123. In FIG. 5, (a) denotesthe channel bit, (b) denotes the output signal from the NRZ convertingunit 121, and (c) denotes an NRZI converted pulse being a record signalas the final output from the record signal processing circuit 111. Therecord signal is outputted by the pick-up 102, and the recordinformation under the control of the servo circuit section 104.

With the configuration according to the present invention, whether theDC control bit (see FIG. 3(g)) executed by the modulated data producingsection 109 is set to [0] or [1] in the case of the recording frameequivalent to the recording area for the additional data is determinedpartially based on the constituent bit of the additional data.

For instance, a specific recording frame is selected as an additionaldata recording area, a certain DC control bit in the selected recordingframe, for instance, a DC control bit where three DC control bits atpositions a, b, and c in the 28 DC control bits set as a recording frameis determined based on the constituent bit of the additional data, isused, and the bit value [0] or [1] is determined based on theconstituent bit of the additional data for the specific DC control bits.This processing allows for recording the additional data on themodulated data.

Returning to the configuration in FIG. 1, the explanation of theconfiguration of the information recorder/processor according to thepresent invention continues. In FIG. 1, the additional data is inputtedto the additional data error correcting/coding section 105, and a codingprocessing for adding an error correcting code is executed. Theadditional data herein refers to the data configured with variousinformation such as encryption key information, encryption keyproduction information, contents reproduction control information,contents copying control information, and other contents attributeinformation.

The DC control bit specifying unit 110 inputs a bit string of theadditional data added to the error correcting code from the additionaldata error correcting/coding section 105. For instance, a data string of[0, 0, 0, 1, 0, 0, 0 . . . ] is inputted. The bit string includes any ofthe additional data including encryption key information, encryption keyproduction information, contents reproduction control information,contents copying control information, and other contents attributeinformation as well as the error correcting code for the additionaldata.

The additional data recording area control section 107 detects a set-uparea for the additional information bit based on the output data fromthe main data error correcting/coding section 106. Namely, a produceddata area for a specific recording frame as a set-up area for theadditional information bit is detected.

When the produced data area for a specific recording frame as a set-uparea for the additional information bit is detected, the additional datarecording area control section 107 sets the switch 108 on the side ofthe DC control bit specifying unit 110 and outputs the DC control bitinformation determined by the DC control bit specifying unit 110 basedon the additional information to the modulated data producing section109.

The modulated data producing section 109 determines and set a value ofthe DC control bit added to the recording frame corresponding to theadditional data recording area based on an instruction from the DCcontrol bit specifying unit 110.

The DC control bit specifying unit 110 inputs a bit string of theadditional data added with an error correcting code, for instance, a bitstring such as [0, 0, 0, 1, 0, 0, 0 . . . ] from the additional dataerror correcting/coding section 105, and determines the value of the DCcontrol bit in a specific position in the recording frame as a set-uparea for the additional information bit according to each bit value [0]or [1].

For the processing procedure, for instance, no matter for the recordingframe as the set-up area for the additional information bit or thenormal recording frame except for the set-up area for the additionalinformation bit, the bit value determined based on the DSV is set as theDC control bit as in the past. Namely, assuming that a value accumulatedwith the bit [0] in a recording bit series (NRZI conversion signal)regarded as [−1] and the bit [1] as [+1] is DSV, either [0] or [1] for aDC control bit is selected and inserted so as to minimize the deviationof the DSV from 0.

In FIG. 1, the DSV measuring section 112 executes DSV measurement foreach recording frame, the result of the measurement is inputted to theDSV-based DC control bit setting section 113, and the DSV-based DCcontrol bit setting section 113 executes the DC control bit set-upprocessing based on the DSV, namely, sets the bit value capable offurther reducing the deviation of the DSV from 0 as the value of the DCcontrol bit.

After the set-up of the DC control bit based on the DSV, a replacingprocessing of the bit values is performed only on the DC control bit inthe specific position in the recording frame as a set-up area for theadditional information bit.

The bit value determined based on the additional data is outputted tothe modulated data producing section 109 via the switch 108 by the DCcontrol bit specifying unit 110, and only the DC control bit in thespecific position associated to the additional data is replaced with thevalue instructed by the DC control bit specifying unit 110. For otherpositions, the values set by the DSV-based DC control bit settingsection 113 are maintained. The switching control for the switch 108 isexecuted by the additional data recording area control section 107 andoutputs the output from the DC control bit specifying unit 110 to themodulated data producing section 109 only when the processing of theadditional data-associated DC control bit adjustment recording frame isexecuted.

FIG. 1 is a block diagram schematically illustrating configuration ofand processing by the information recorder/processor according to thepresent invention, and the actual processing for setting a DC controlbit based on the determination as to which of a bit associated toadditional data or a bit based on a result of DVS measurement isexecuted by a control section such as a CPU executing a programdescribing a processing sequence for setting a DC control bit.Therefore, in the information recorder/processor, hardware correspondingto discrete components such as a switch shown in FIG. 1 and the like isnot always indispensable. The recording frame can be executed onhardware enabling production of a recording frame including a controlsection for executing processing following a specified program, a CPU asa data processing section, and a memory such as a storage unit forstoring therein data, parameters, and the like.

The processes executed in such blocks as the error correcting/codingsection, the DC control bit specifying unit, and modulated dataproducing sections shown in FIG. 1 is executed on the hardware includinga control section for executing processing following a specifiedprogram, a CPU as a data processing section, and a memory such as astorage unit for storing therein data, parameters, and the like, and inFIG. 1, each block corresponds to a single function for facilitatingunderstanding of the present invention.

Details of the processing for setting a DC control bit associated toadditional data executed by the DC control bit specifying unit 110 shownin FIG. 1 are described below.

FIGS. 6(A) and 6(B) are views illustrating details of the BIS block 213and BIS cluster 214 produced based on the user control data 211 duringthe modulated data producing processing described by referring to FIGS.2(a) to 2(d) and FIGS. 3(d) to 3(h).

As described by referring to FIGS. 2(a) to 2(d) and FIGS. 3(d) to 3(h),the user control data (UCD) 211 is associated with the 16×9 bytesphysical address data 212, and after the access block 212 with the sizeof 24 columns×30 rows is produced, the BIS block 213 is produced as adata block with a parity of 32 columns added thereto as described inFIG. 6(A) for the access block 212.

The BIS cluster 214 with the size of 3 columns×496 rows as shown in FIG.6(B) is produced by the interleaving to the BIS block 213.

As shown in FIG. 6(B), the BIS cluster includes one unit formed with aphysical address extending over 3 rows, user control data (UCD)extending over 12 rows, and a parity extending over 16 rows, and theunit has the size of 3 columns×31 rows. The BIS cluster 214 has the sizeof 3 columns×496 rows and include units 0 to 15, namely 16 units in all.

As shown in FIG. 7, the BIS cluster having the configuration asdescribed with reference to FIGS. 2(a) to 2(d) and FIGS. 3(d) to 3(h) isinserted line by line between quarter data I to VI of the LDC cluster204 set based on user data such as contents, thus the ECC cluster 231being produced.

As shown in FIG. 7, the ECC cluster is set by combining the LCD clusterhaving the size of 152 columns and 496 rows with the BIS cluster havingthe size of 3 columns×496 rows.

As described by referring to FIGS. 6(A) and 6(B), the BIS cluster has aphysical address, user control data (UCD), and a parity, which arearranged in different rows respectively. Therefore the BIS cluster (i,ii, iii) included in each of the 496 rows constituting the ECC cluster231 denotes any of the physical address, user control data (UCD), andparity.

AS shown in FIG. 8, a particular row selected from the 496 rowsconstituting the ECC cluster 231 is set as an additional data-associatedDC control bit adjustment frame 301.

A portion of a DC control bit set in the additional data-associated DCcontrol bit adjustment frame 301 is set as a DC control bit having a bitvalue decided by the additional data constituent bit. In the DC controlbit adjustment recording frame 302 shown in FIG. 8, the DC control bitcorresponding to constituent bit for additional data is set at each ofthe control bit positions #1, #10, and #20 in the recording frame.

As shown in FIG. 8, a recording frame is divided into 28 sections #0 to#27, and 1-bit DC control bit of [0] or [1] is set in each sections. TheDC control bit at a specified position among the 28 positions forsetting a DC control bit is set as a DC control bit associated to theadditional data.

As described above, a DC control bit is set, as a rule, as a bit valuedecided based on DSV. In other words, generally [0] or [1] is selectedand inserted as a DC control bit so that the difference between DSV andzero will be minimized assuming bit [0] in the recording bit series(NRZI conversion signal) as [−1] and bit [1] as [+1]. In this case DSVindicates a sum of the bits.

However, as for the DC control bit corresponding to an additional dataconstituent bit (DC control bit at each of the positions #1, #10, #20 inthe recording frame 302 shown in FIG. 8), the rule described above isnot employed, and a value decided based on the additional dataconstituent bit value is set.

In FIG. 8, a DC control bit associated to additional data constituentbit is provided at each of the three positions #1, #10, and #20 in theDC control bit adjustment recording frame 302, and a DC control bit at aposition other than the three positions described above is set as a DCcontrol bit decided based on the DSV measurement. However, a valuedecided based on the additional data constituent bit value is set foreach of these three bits.

In the example described above, each of the positions #1, #10, and #20in the DC control bit adjustment recording frame is employed as aposition for setting a DC control bit based on additional data, but aposition for setting an additional data-associated DC control bit is notlimited to the three positions #1, #10, and #20, and a DC controlposition can be set at any position.

A number of positions each for setting a DC control bit is not limitedto three, and a bit based on additional data can be set at any number ofpositions in the DC control bit adjustment recording frame. Aninformation reproducer for decoding additional data decodes theadditional data by executing the processing for decoding the additionaldata based on the information concerning prespecified positions each forsetting a DC control bit associated to additional data.

Correspondence between the three positions, at each of which a bit basedon additional data is set, within the DC control bit adjustmentrecording frame and [0] or [1] as an additional data constituent bit is,for instance, as shown in FIG. 9.

In the example shown in FIG. 9, when the three bits in the DC controlbit adjustment recording frame has the same parity of [0, 0, 0] or [1,1, 1], the additional data constituent bit is set to [0], and when thethree bits in the DC control bit adjustment recording frame aredifferent, namely when the set of three bits is any of [0, 0, 1], theadditional data constituent bit is set to [1].

In the example shown in FIG. 9, the additional data constituent bit isset to [0] or [1] according to the three bits in the DC control bitadjustment recording frame, but the present invention is not limited tothis configuration, and various configurations are possible includingthat shown in FIG. 10 in which the two additional data constituent bitsare set to [0, 0], [0, 1], [1, 0], and [1, 1] according to a set ofthree bits in the DC control bit adjustment recording frame.

In either one of the configurations shown in FIG. 9 and FIG. 10, aplurality of DC control bit information are associated to one additionaldata bit information. In other words, in FIG. 9, two sets of DC controlbits of [0, 0, 0] and [1, 1, 1] are associated to one additional dataconstituent bit of [0], and six sets of control bits, namely [0, 0, 1]to [1, 0, 1] are associated to one additional data constituent bit of[1]. Also in the example shown in FIG. 10, two sets of DC controls bitsof [0, 0, 0] and [1, 1, 1] are associated to one set of additional dataconstituent bits [0, 0], and any of other sets of additional dataconstituent bits of [0, 1], [1, 0], and [1, 1] is associated to aplurality of (two) sets of DC control bits.

With this configuration, in setting a DC control bit based on a resultof DSV measurement, when the same DC control bit as that based onadditional data constituent bit is set, the set value can be replacedwith another value different from the DC control bit based on DSVmeasurement. Because the replacement as described above is possible,when it is tried to copy data, it is possible to decide whether thecopying operation is legal or not.

For instance, in the processing based on the setup shown in FIG. 9, inthe case where the three bits in the DC control bit adjustment recordingframe for storing therein additional data constituent bit [0] (forinstance, at the positions #1, #10, and #20) is [0, 0, 0] when DCcontrol bits are set based on DSV measurement, the DC control bitinformation set to the additional data bit of [0] is changed to adifferent value, so that a set of [1, 1, 1] is obtained. With thisprocessing, when data is copied, whether the data is copied or not caneasily be determined.

For instance, in the case where the three bits in the DC control bitadjustment recording frame for storing therein additional dataconstituent bit are [0, 0, 0] when DC control bits based on DSVmeasurement are set, by replacing the control bits with [1, 1, 1] andthen recording the data, in a case where a recording medium with therecorded data based on the recording frame recorded therein is set on aninformation reproducer and the data is demodulated, reproduced, andre-recorded in another recording medium, namely when the data is copied,and when the processing for additional DC control bits based on the DSVmeasurement is newly executed, the DC control bits of [0, 0, 0] are setat the additional data-associated DC control bit positions, and thecontrol bits are different from the original DC control bits of [1, 1,1]. Therefore, the fact that copied data is recorded in the recordingmedium can easily be detected.

To make it possible to determine whether data is copied or not, aplurality of DC control bit information is assigned to bit informationassociated to one additional data.

Details of the processing for storing additional data according to thepresent invention are described below with reference to FIGS. 11(a) and11(b), and FIGS. 12(a) and 12(b). FIGS. 11(a) and 11(b), and FIGS. 12(a)and 12(b) are views each showing an example like that shown in FIG. 9,namely an example in which DC control bits at three positions #1, #10,and #20 in the additional data-associated DC control bit adjustmentrecording frame are selected, and 1-bit additional data constituent bitof [0] or [1] is associated according to the three DC control bits.

FIGS. 11(a) and 11(b) are views illustrating the processing foradjusting DC control bits in the additional data-associated recordingframe when the additional data constituent bit is [0].

FIG. 11(a) illustrates a case where DC control bits of [0, 1, 0] are setat three additional data-associated DC control bit setting positions(for instance, #1, #10, and #20) based on DSV measurement.

As shown in FIG. 11(a), the DC control bits of [0, 1, 0] decided basedon DSV measurement are set at the additional data-associated DC controlbit setting positions (#1, #10, and #20) within the recording frame 321.

Because the constituent bit of the additional data is [0], it isnecessary to set any of [0, 0, 0] or [1, 1, 1] at the additionaldata-associated DC control bit setting positions based on the tableshown in FIG. 9. In this example, the DC control bits set based on DSVmeasurement are [0, 1, 0], and therefore [0, 0, 0] requiring change ofonly one bit is selected for the DC control bits for the additionaldata, and the DC control bit at the position #10 is changed from [1] to[0], thus the additional data-associated DC control bit adjustmentrecording frame 322 as shown in the middle stage in FIG. 11(a) beingproduced. The DC control bits can be changed to [1, 1, 1], but a numberof changed bits should be minimized to reduce influence over DSV.

Then conversion of 2-bit data to 3-bit data is performed according tothe RLL (1, 7) run length limited to produce the modulated recordingframe 323 with Sync code set therein.

This processing is executed by the modulated data producing section 109shown in FIG. 1, and the recording frame 321 with DSV control bits basedon DSV measurement has the configuration as shown in FIG. 1 and includestherein DC control bits decided by the DSV base DC control bit settingsection 113 based on DSV measurement by the DSV measuring section 112.

As described with reference to FIG. 8, a 1-bit DC control bit is set ineach of the 28 sections #0 to #27 of a recording frame. FIGS. 11(a) and11(b) show only three DC control bit values at the additionaldata-associated DC control bit positions (#1, #10, and #20), and DCcontrol bits based on DSC measurement information are stored at other DCcontrol bit positions.

Only the three DC control bits at the additional data-associated DCcontrol bit positions (#1, #10, and #20) are objects for replacementwith another value. In the DC control bit specifying unit 110 shown inFIG. 1, values of three additional data-associated DC control bits aredecided based on additional data, and this decided bit information isinputted to the modulated data producing section 109, and three DCcontrol bits at the additional data-associated DC control bit positions(#1, #10, and #20) are replaced with different values respectively.

In the modulated data producing section 109 shown in FIG. 1, theprocessing for replacement of bit values is executed for the DC controlbits at the three additional data-associated DC control bit positions(#1, #10, and #20) based on input information from the DC control bitspecifying section 110. With the processing, the recording frame 322with the DC control bits of [0, 0, 0] based on additional data settherein is produced.

Then conversion of 2-bit information to 3-bit information is performedaccording to the RLL (1, 7) run length limited to produce the modulatedrecording frame 323 with Sync code set therein.

The modulated recording frame 323 produced in the modulated dataproducing section 109 is converted to an NRZI signal (Refer to FIG. 5)in the recording signal processing circuit 111 shown in FIG. 1, and isrecorded in the information recording medium 101.

AS a result of processing shown in FIG. 11(a), three DC control bits of[0, 0, 0] are set at the three additional data-associated DC control bitpositions (#1, #10, and #20) in the additional data-associated recordingframe.

In the reproducer for reproducing data, information concerning the threeDC control bits at the three additional data-associated DC control bitpositions (#1, #10, #20) in the additional data-associated recordingframe are detected. As a result of detection, three bits of [0, 0, 0]are detected as DC control bit information, and it is determined on this3-bit information that a bit value in the additional data is [0].

The reproducer acquires additional data constituent bit values for aplurality of additional data-associated recording frames to acquiren-bit additional data such as an encryption key based on a plurality ofanalyzed bit values.

The reproducer for reproducing data stores the correspondence tableshown in FIG. 9 or FIG. 10 in a storage section, or a program forexecuting an algorithm for interpreting additional data associated tothe correspondence table in the storage section, and also determines theadditional data bit values based on the additional data-associated DCcontrol bits by referring to the correspondence table or according tothe program for executing the algorithm for interpreting the additionaldata. The processing for detecting additional data in the reproducer isdescribed in detail below.

FIG. 11 (b) illustrates processing in a case where, although aconstituent bit of additional data is [0] like in FIG. 11(a), DC controlbits of [0, 0, 0] based on DSV measurement are set at three DC controlbit setting positions (for instance, #1, #10, and #20) for setting DCcontrol bit associated to additional data.

As shown in FIG. 11(b), the DC control bits of [0, 0, 0] based on DSVmeasurement are set at additional data-associated DC control bit settingposition in the recording frame 331.

As the constituent bit of additional data is [0], it is necessary to setany of [0, 0, 0] or [1, 1, 1] at the additional data-associated DCcontrol bit setting positions based on the table shown in FIG. 9. Inthis example, the DC control bits set based on DSV measurement are [0,0, 0], so that the DC control bit values corresponding to theconstituent bit [0] of the additional data has already been set.

In this case, as described above, to enable determination as to whetherdata is copied or not, the processing is performed to replace the bitinformation with different DC control bit information corresponding tothe constituent bit of [0] in the additional data. In this case, the DCcontrol bit information is changed to [1, 1, 1] corresponding to theconstituent bit [0] in the additional data.

As shown in FIG. 11(b), all of the DC control bits associated to theadditional data at the positions #1, #10, and #20 are changed from [0]to [1] to produce the additional data-associated DC control bitadjustment recording frame 332.

Then conversion of 2-bit information to 3-bit information is executedaccording to the RLL (1, 7) run length limited to produce a demodulatedrecording frame 333 with Sync code set therein.

This processing is executed by the demodulated data producing section109 shown in FIG. 1. The demodulated recording frame 333 generated inthe modulated data producing section 109 is converted to an NRZI signal(Refer to FIG. 5) in the record signal processing circuit 111 as shownin FIG. 1 and is recorded in the information recording medium 101.

As a result of processing shown in FIG. 11(b), the three DC control bitsof [1, 1, 1] are set at the additional data-associated DC control bitpositions (#1, #10, and #20) in the additional data-associated recordingframe.

The reproducer for reproducing data detects the three DC control bitinformation of [1, 1, 1] at the additional data-associated DC controlbit positions (#1, #10, and #20) in the additional data-associatedrecording frame, and determines that the bit value of the additionaldata is [0] based on the 3-bit information.

FIGS. 12(a) and 12(b) are views illustrating the processing foradjusting DC control bits in the additional data-associated recordingframe when a constituent bit of the additional data is [1].

FIG. 12(a) is an example of process executed when DC control bits of [0,0, 0] based on DSV measurement are set at three DC control bit settingpositions (for instance, #1, #10, and #20) each for setting a DC controlbits associated to additional data.

As shown in FIG. 12(a), in the recording frame 341, the DC control bitsof [0, 0, 0] based on DSV measurement are set at the additionaldata-associated DC control bit setting positions.

Because a constituent bit of the additional data is [1], it is necessaryto set any of [0, 0, 1] to [1, 0, 1] based on the table shown in FIG. 9at the additional data-associated DC control bit setting positions. Inthis example, the DC control bits set based on DSV measurement are [0,0, 0], so that [0, 1, 0] requiring change of only one bit is selected asthe DC control bits for the additional data, and the DC control bit (atposition #20) is changed from [0] to [1] to produce the additionaldata-associated DC control bit adjustment recording frame 342 as shownin the middle of FIG. 12(a). Any other one among [0, 0, 1] to [1, 0, 1]can be set. To minimize influence over DSV, it is preferable to selectand execute the processing requiring minimum change of bits.

Then, conversion of 2-bit information to 3-bit information is performedaccording to the RLL (1, 7) run length limited for modulation to producea modulated recording frame 343 with Sync code set therein.

This processing is executed by the modulated data producing section 109shown in FIG. 1. The modulated recording frame 343 produced in themodulated data producing section 109 is converted to an NRZI signal(Refer to FIG. 5) in the recording signal processing circuit 111 shownin FIG. 1 and is recorded in the information recording medium 101.

Because a result of the processing shown in FIG. 12(a), DC control bitsof [0, 0, 1] are set at the three DC control bit setting positions (forinstance, #1, #10, and #20) each for setting a DC control bitsassociated to additional data in the additional data-associatedrecording frame.

The reproducer for reproducing data detects the three DC control bitinformation at the additional data-associated DC control bit settingpositions (for instance, #1, #10, and #20) in the additionaldata-associated recording frame, and detects the three DC control bitsof [0, 0, 1] as a result of the detection. The reproducer determinesbased on this 3-bit information that a bit value data of the additionaldata is [1].

FIG. 12(b) illustrates an example of processing in a case where,although a constituent bit of additional data is [1] like in FIG. 12(a),DC control bits of [0, 1, 0] based on DSV measurement are set at thethree DC control bit setting positions (for instance, #1, #10, and #20)each for setting a DC control bit associated to the additional data.

As shown in FIG. 12(b), DC control bits of [0, 1, 0] based on DSVmeasurement are set at the additional data-associated DC control bitsetting positions in the recording frame 351.

Because a constituent bit of the additional data is [1], it is necessaryto set any of [0, 0, 1] to [1, 0, 1] based on the table shown in FIG. 9at the additional data-associated DC control bit setting positions. Inthis example, the DC control bits set based on DSV measurement are [0,1, 0], so that the DC control bit values corresponding to theconstituent bit [1] of the additional data have been set.

As described above, to determined whether the data is copied or not, theprocessing for replacing the DC control bit information with differentDC control bit information corresponding to the constituent bit [1] ofthe additional data is executed. For instance, [0, 1, 1] requiringchange of only one bit is selected as the DC control bits associated tothe additional data; so that the DC control bit at the position #10 ischanged from [0] to [1] to produce an additional data-associated DCcontrol bit adjustment recording frame 352 as shown in the middle ofFIG. 12(b). Of the DC control bits [0, 0, 1] to [1, 0, 1], any patternother than [0, 1, 0] may be set. However, to minimize influence overDSV, it is preferable to execute the processing requiring minimum changeof bits.

Then conversion of 2-bit information to 3-bit information is executedfor modulation according to the RLL (1, 7) run length limited to producea modulated recording frame 353 with Sync code set therein.

This processing is performed by the modulated data producing section 109shown in FIG. 1. The modulated recording frame 353 produced in themodulated data producing section 109 is converted to an NRZI signal(Refer to FIG. 5) by the record signal processing circuit 111 shown inFIG. 1, and is recorded in the information recording medium 101.

As a result of the processing shown in FIG. 12(b), DC control bits of[0, 1, 1] are set at the three additional data-associated DC control bitsetting positions (for instance, #1, #10, and #20)in the additionaldata-associated recording frame.

The reproducer for reproducing data detects the three DC control bits atthe three DC control bit setting positions (for instance, #1, #10, and#20) in the additional data-associated recording frame, and detects thethree DC control bits of [0, 1, 1] as a result of detection. Thereproducer determines based on the 3-bit information that a bit value ofthe additional data is [1].

A processing sequence of recording additional data executed by theinformation recorder/processor according to the present invention isdescribed with reference to FIG. 13 and FIG. 14.

Additional data having been subjected to error correction/coding isinputted in step S101. This data is outputted from the additional dataerror correcting/coding section 105 shown in FIG. 1. The additional dataincludes various types of information such as encryption keyinformation, encryption key production information, contentsreproduction control information, contents copying control information,and other contents attribute information, and a bit array includingadditional data with error correction code added thereto such as [0, 0,0, 1, 0, 0, 0 . . . ] is inputted.

In step S102, recording bits are acquired one by one from theconstituent bit arrays of the additional data such as, for instance, [0,0, 0, 1, 0, 0, 0 . . . ] sequentially. In this processing flow, theprocessing is executed bit by bit for the constituent bits of additionaldata, but as described with reference to FIG. 10, in the configurationin which DC control bit information is associated to each of 2-bitadditional data bits [00] to [11], the additional data bits areprocessed two bits by two bits, and two bits are sequentially extractedfor processing from an array of additional data such as, for instance,[0, 0, 0, 1, 0, 0, 0 . . . ]. An example of processing additional dataconstituent bits one by one is described below.

In step S103, the processing for modulating an additionaldata-associated recording frame (RF) is executed, and DC control bitinformation set based on DSV measurement is acquired. The DC control bitinformation acquired in this step indicates bit information at DCcontrol bit positions associated to additional data in the additionaldata-associated recording frame (RF). As described above, for instance,when DC control bits associated to additional data are set at thepositions #1, #10, and #20 in the recording frame, information on the DCcontrol bit at the positions #1, #10, and #20 is acquired.

In step S104, determination is made as to whether record bits, namelybit values sequentially extracted from a bit array of additional datasuch as [0, 0, 0, 1, 0, 0, 0 . . . ] are [0] or not respectively.

When the extracted bit is [0], processing moves to step S105. When theextracted bit is [1], the processing moves to step S106.

When the record bit is [0], in step S105 shown in FIG. 14, determinationis made as to whether the DC control bit information acquired in stepS103, namely bit information at the additional data-associated DCcontrol bit positions in the additional data-associated recording frame(RF) is set as a bit array corresponding to the additional data [0] ornot.

More specifically, when the processing based on the correspondence, forinstance, shown in FIG. 9 is executed, determination is made as towhether [0, 0, 0] or [1, 1, 1] are set at the additional data-associatedDC control bit positions as DC control bits based on DSV measurement ornot.

When a bit array corresponding to the additional data bit [0] is set asDC control bits based on DSV measurement (Yes in step S105), theprocessing moves to step S107, and a bit array corresponding to theadditional data bit [0] already set is replaced with a different bitarray corresponding to the additional data bit [0].

More specifically, when [0, 0, 0] are set as DC control bits based onDSV measurement, the processing for replacing [0, 0, 0] with [1, 1, 1]is executed. When [1, 1, 1] is set as DC control bits based on DSVmeasurement, the processing for replacing [1, 1, 1] with [0, 0, 0] isexecuted.

When it is determined No in step S105, namely that a bit arraycorresponding to the additional data bit [0] is not set as a DC controlbit based on DSV measurement, the processing moves to step S108, theprocessing is performed for replacing the bit array with another bitarray corresponding to the additional data bit [0]. More specifically,the processing is performed for replacing bit values at the additionaldata-associated DC control bit setting positions with a bit array of [0,0, 0] or [1, 1, 1] corresponding to the additional data bit [0].

On the other hand, when the record bit is [1], in step S106 shown inFIG. 14, determination is made as to whether the DC control bitinformation acquired in step S103, namely the bit information atadditional data-associated DC control bit positions in the additionaldata-associated recording frame (RF) is set as a bit array correspondingto the additional data bit [1] or not.

More specifically, when the processing based on the correspondence, forinstance, shown in FIG. 9 is executed, determination is made as towhether any of [0, 0, 1] to [1, 0, 1] is set as DC control bits based onDSV measurement at the additional data-associated DC control bit settingpositions or not.

When a bit array corresponding to the additional data bit [1] is set asa DC control bit based on DSV measurement (Yes in step S106), theprocessing moves to S109, and a bit array corresponding to theadditional data bit [1] already set is replaced with a different bitarray corresponding to the additional data bit [1].

More specifically, for instance, when [0, 0, 1] is set as DC controlbits based on DSV measurement, the DC control bits of [0, 0, 1] isreplaced with any of different bit arrays corresponding to theadditional data constituent bit [1], namely with any of [0, 1, 0], [1,0, 0], [0, 1, 1], [1, 1, 0], and [1, 0, 1].

When a result of determination in step S106 is No, namely when a bitarray corresponding to the additional data bit [1] is not set as DCcontrol bits based on DSV measurement, the processing flows to stepS110, and the DC control bits is replaced with a bit array correspondingto the additional data bit [1]. More specifically, bit values at theadditional data-associated DC control bit setting positions are replacedwith any of bit arrays [0, 0, 1] to [1, 0, 1] corresponding to theadditional data bit [1] shown in FIG. 9.

In step S111, the additional data-associated recording frame with DCcontrol bits controlled according to the additional data set therein ismodulated. The processing for modulation is executed in the modulateddata producing section 109 shown in FIG. 1.

In step S112, whether the processing of a final bit of the additionaldata has been finished or not is determined, and when there is data notprocessed yet, the processing steps beginning with step S102 arerepeated.

When it is determined in step S112 that there is no data not processedyet, it indicates completion of the processing described above, andrecorded data with additional information bit inserted therein isproduced according to the processing sequence as described above.

As described above, the processing flows shown in FIG. 13 and FIG. 14are examples in which additional data is processed bit by bit, and whenit is determined that the correspondence between the additional databits based on a 2-bit unit and the DC control bit information has beenset as shown in FIG. 10, the processing is executed by two bits.Alternatively also the configuration is possible in which thecorrespondence between 3 bits or more in additional data and DC controlbit information or correspondence between any number of bits in theadditional data and any number of DC control bits is set, and processingis performed according to the correspondence set up as described above.

Configuration of the data reproducer for reproducing data from aninformation recording medium with the additional information asdescribed above contents (main data) such as moving pictures or music asdescribed above recorded therein and a sequence of reproductionprocessing are described below.

Configuration of the data reproducer and processing for reproducing dataare described above with reference to FIG. 15. The data reproducerincludes an information recording medium 401, a pick-up 402 for readingout data from the information recording medium 401, a spindle motor 403for driving the information recording medium 401, a servo circuitsection 404 for controlling the pick-up 402 and spindle motor 403, an RFcircuit section 405 for producing an RF signal by executing signalprocessing such as gain adjustment for a read signal, a synchronicitydetecting section 406 for extracting a sync signal from the RF signal, adata demodulating section 407 for demodulating data, a switch 410 foroutputting a read signal only from the information recording medium toan additional data decoding section 408, an additional data recordingarea detecting section 411 for detecting an additional data area andcontrolling the switch 410, an additional data decoding section 408 fordecoding additional data, a main data error correcting section 412 forcorrecting an error in main data, and an additional data errorcorrecting section 409 for correcting an error in the additional data.

The contents data stored in the information recording medium 401 is, forinstance, encrypted contents data, and additional data stored in theinformation recording medium 401 include key data used for decodingencrypted contents, key production information, contents reproductioncontrol information, contents copying control information, and othercontents attribute information.

The data read via the pick-up 402 from the information recording medium401 is subjected to signal processing such as gain adjustment in the RFcircuit section 405, and is inputted to the synchronicity detectingsection 406. The synchronicity detecting section 406 detects a syncsignal in a record signal, and outputs the detected signal to theadditional data recording area control section 411.

The additional data recording area control section 411 determines arecording area of additional data based on the sync signal inputted fromthe synchronicity detecting section 406, and controls the switch 410based on determination information. With this switch control, arecording frame in an area required for decoding additional data, namelya recording frame associated to the additional data with DC control bitinformation based on the additional data set therein are inputted to theadditional data decoding section 408 for decoding additional data fromthe data demodulating section 407.

The additional data decoding section 408 executes decoding foracquisition of additional data based on the additional data-associatedrecording frame inputted from the data demodulating section 407. Namelythe additional data decoding section 408 detects the DC control bitinformation based on additional data from the additional data-associatedrecording frame and determines constituent bit of additional data basedon the detected DC control bit value.

In other words, the additional data decoding section 408 acquires valuesof DC control bits, for instance, at the additional data-associated DCcontrol bit setting positions #1, #10, and #20 in the additionaldata-associated recording frame, and determines whether the constituentbit of additional data is [0] or [1] based on the information describedabove.

The additional data decoding section 408 has a storage section having acorrespondence table shown in FIG. 9 or FIG. 10, or executes processingaccording to a program for executing an algorithm for interpreting theadditional data corresponding to the correspondence table. Namely theadditional data decoding section 408 executes the processing fordetermining an additional data bit value based on DC control bitsassociated to additional data by referring to the correspondence tablestored in the storage section or according to the algorithm forinterpreting additional data.

When the data processed in the data demodulating section 407 is arecording frame associated to additional data, the reproducer inputs theframe data via the switch 410 to the additional data decoding section408, and the additional data decoding section 408 acquires DC controlbits at additional data-associated DC control bit setting positions inthe additional data-associated recording frame, and determinesconstituent bits in the additional data based on the information.

The additional data decoding section 408 executes the processingdescribed above based on the recording frame with additional datainputted intermittently set therein, and acquires additional data suchas, for instance, n-bit information key data, key productioninformation, contents reproduction control information, contents copyingcontrol information, and other attribute information of the contents.The additional data includes error correction code as described inrelation to the data recorder/producer and is outputted after errorcorrection in the additional data error correcting section 409.

When the additional data is, for instance, key information used fordecoding contents, the additional data is outputted to the decodingsection for decoding the contents. When the additional data is contentsreproduction control information, the data is outputted to thereproduction control section.

In a case of the general data other than additional data, data read outfrom an information recording medium is outputted from the syncdetecting section 406 to the data demodulating section 407 and issequentially subjected to data conversion described by referring toFIGS. 2(a) to 2(d) and FIGS. 3(d) to 3(h) above, and then the reproduceddata is acquired.

Also main data, which is demodulated data, includes an error correctioncode like that in the additional data, and is outputted after the erroris corrected in the main data error correcting section 412.

When the output data is, for instance, encrypted contents, the data isdecoded by using an encryption key that can be produced based on the keyproduced information outputted as additional data, and then is outputtedvia an output unit such as a display or a speaker.

A sequence of reproduction including a step of reading out additionalinformation is described below with reference to FIG. 16. The processingshown in FIG. 16 is executed by the reproducer shown in FIG. 15.

In step S201, an RF signal is produced based on a signal read out fromthe information recording medium. In step S202, demodulation is carriedout based on the RF signal, and a recording frame associated toadditional frame, namely a recording frame having DC control bit valuesdecided based on the additional data is acquired as data in the processof demodulation. The acquired additional data-associated recording frameis inputted from the data demodulating section 407 shown in FIG. 15 tothe additional data decoding section 408.

In step S203, the additional data decoding section 408 executes thedecoding processing for acquiring additional data based on theadditional data-associated recording frame inputted from the datademodulating section 407. In other words, DC control bit informationbased on the additional data is extracted from the additionaldata-associated recording frame. For instance, values of DC controlbits, for instance, at the positions #1, #10, and #20 are acquired.

In step S204, determination is made as to which of the additional databit [0] and [1] the DC control bit array corresponds to. As describedabove, the additional data decoding section 408 determines additionaldata bit values by executing the correspondence table shown in FIG. 9 orFIG. 10, or the algorithm for interpreting additional data associated tothe corresponding table to determine the bit values based on theadditional data-associated DC control bits.

When it is determined in step S204 that the acquired values of DCcontrol bits correspond to the additional data bit of [0], it isdetermined in step S205 that the additional data bit is [0]. When it isdetermined in step S204 that the acquired DC control bit valuescorrespond to the additional data bit of [1], it is determined in stepS206 that the additional data bit is [1].

In step S207, whether the bit is a final bit of the additional data ornot is determined. When it is determined that there is still any bit notprocessed, the processing steps beginning with step S202 are repeateduntil a final bit of the additional data is processed.

In the example of processing described above, 1-bit additional data isanalyzed. However, when the correspondence between 2-bit additional dataand DC control bit information is set as shown in FIG. 10, additionaldata analysis is carried out two bits by two bits. Furthermore, theconfiguration is possible in which correspondence between 3 or more bitsof additional data and DC control bit information is set, or in whichcorrespondence between an arbitrary number of bits in the additionaldata and DC control bit information is set, and the processing isexecuted according to the correspondence set as described above.

The present invention is described in detail above with reference toparticular embodiments of the present invention. However, it is obviousthat those skilled in the art can modify or introduce alternative forthe present invention without departing from the gist of the presentinvention. In other words, the embodiments are described above for thepurpose of disclosure, and the present invention is not limited to theembodiments described above. To understand gist of the presentinvention, claims attached hereto should be referred to.

The series of processing steps described above can be executed byhardware, by software, or by a combination of hardware and software.When the processing sequence is executed by software, a programdescribing the processing sequence is installed for execution in amemory of a computer with dedicated hardware incorporated therein, orcan be installed in a general-purpose computer capable of executingvarious types of processing.

For instance, the program can previously be recorded in a hard disk or aROM (Read Only Memory) as a recording medium. Alternatively the programcan be stored (recorded) temporally or permanently in a removablerecording medium such as a flexible disk, a CD-ROM (Compact Disk ReadOnly Memory), an MO (Magneto-optical) disk, a DVD (Digital VersatileDisk), a magnetic disk, and a semiconductor memory. The removablerecording medium as described above can be provided as the so-calledpackage software.

The program can be installed from the removable recording medium asdescribed above in a computer, and further can be transferred from adown-load site to a computer by means of radio communication, or can betransferred through a wired network such as LAN (Local Area Network) andthe Internet to a computer. The computer receives the programtransferred as described above and can install the program in arecording medium such as a hard disk or the like incorporated therein.

The various processing steps described above are not only executedtime-sequentially according to the descriptions, and can be executedconcurrently or discretely according to a processing capability of adevice used for the processing or according to the necessity. The termof system as used herein indicates configuration of logical connectionof a plurality of devices, and the devices are not always required to beprovided within one housing.

INDUSTRIAL APPLICABILITY

As described above, with the configuration according to the presentinvention, in a recorder/processor capable of recording various types ofadditional data such as key information used for decoding contents, keyproduction information, contents reproduction control information, andcopying control information in an information recording medium, bitvalues set at a plurality of DC control bit information settingpositions in an additional data-associated recording frame as an areafor burying additional data therein are decided according to constituentbit information of the additional data. Further in a reproduceraccording to the present invention, additional constituent bitinformation can be acquired by detecting bit values at specified DCcontrol bit positions in an additional data-associated recording frame.With the configuration as described above, for instance, theconfiguration is realized in which additional information such as keyinformation used for decoding contents, key production information,contents reproduction control information, and copying controlinformation is embedded with a format hardly analyzed, yet the data canaccurately be read out for reproduction. Therefore, the presentinvention can be applied to an information recorder/processor, aninformation reproducer, and an information recording medium used forrecording and reproducing contents requiring protection of copyrightwith the format hardly analyzed with such additional information as keyinformation used for decoding contents, key production information,contents reproduction control information, and copying controlinformation required to be embedded therein.

1. An information recorder/processor comprising: a modulated dataproducing section for setting a DC control bit to data to be recordedand executing data modulation to produce a modulated recording frame asa record unit of data; and a DC control bit specifying section forspecifying a bit value set at an additional data-associated DC controlbit setting position selected from a plurality of DC control bit settingpositions contained in a additional data-associated recording framebased on additional data constituent bit information, wherein saidmodulated data producing section executes processing for setting a bitvalue at the additional data-associated DC control bit position in saidadditional data-associated recording frame according to an instructionby said DC control bit instruction section.
 2. The informationrecorder/processor according to claim 1, wherein said DC control bitspecifying section sets a plurality of DC control bit positions includedin said additional data-associated recording frame as additionaldata-associated DC control bit positions, and decides a plurality of bitvalues at a plurality of the additional data-associated DC control bitpositions based on constituent bit information of the additional data.3. The information recorder/processor according to claim 1, wherein saidDC control bit specifying section decides one bit information selectedfrom a plurality of different DC control bit information correspondingto constituent bit information of one additional data as bit informationto be set at an additional data-associated DC control bit position, andalso decides, when bit information based on DSV measurement at theadditional data-associated DC control bit position is identical to DCcontrol bit information corresponding to additional data constituent bitinformation to be set, bit information different from the bitinformation based on DSV measurement as bit information to be set at theadditional data-associated DC control bit position.
 4. The informationrecorder/processor according to claim 1, wherein said DC control bitspecifying section decides one bit information selected from a pluralityof different DC control bit information associated to one additionaldata constituent bit information as bit information set at an additionaldata-associated DC control bit position, and also decides bitinformation requiring minimum number of bits changed from bitinformation based on DSV measurement at the additional data-associatedDC control bit position as bit information to be set at the additionaldata-associated DC control bit position.
 5. The informationrecorder/processor according to claim 1, wherein said DC control bitspecifying section decides different bit information as bit informationto be set at the additional data-associated DC control bit positionaccording to a single constituent bit of 0 or 1 in the additional data.6. The information recorder/processor according to claim 1, wherein saidDC control bit specifying section decides different bit information asbit information to be set at the additional data-associated DC controlbit position according to each of a plurality of additional dataconstituent bit arrays in the additional data.
 7. The informationrecorder/processor according to claim 1, wherein said additional data isset as constituent information of at least any one of encryption keyinformation, encryption key production information, contentsreproduction control information, and content copying controlinformation for contents to be stored in said information recordingmedium.
 8. The information recorder/processor according to claim 1,wherein said modulated data producing section produces a modulatedrecording frame by executing data conversion satisfying RLL (1,7) as therun length limited.
 9. The information recorder/processor according toclaim 1, wherein said modulated data producing section executes theprocessing for producing a modulated recording frame, said processingcomprises a step of converting 2-bit information to 3-bit information.10. An information reproducer for executing reproduction processing ofinformation stored in an information recording medium comprising: a datademodulating section for executing demodulation of data read out from aninformation recording medium; and an additional data decoding sectionfor executing analysis of bit information set at an additionaldata-associated DC control bit position included in a recording frameassociated to the additional data and acquiring additional dataconstituent bit information based on a result of the analysis.
 11. Theinformation reproducer according to claim 10, wherein said additionaldata decoding section executes analysis of a plurality of DC controlbits included in said additional data-associated recording frame andacquires bit information previously associated to a bit array to beacquired as additional data constituent bit information according to aresult of analysis.
 12. The information reproducer according to claim10, wherein said additional data decoding section acquires a signalconstituent bit of 0 or 1 in the additional data based on bitinformation set at the additional data-associated DC control bitposition set in one recording frame.
 13. The information reproduceraccording to claim 10, wherein said additional data decoding sectionacquires a plurality of constituent bit information in the additionaldata based on bit information set at the additional data-associated DCcontrol bit positions set in one recording frame.
 14. The informationreproducer according to claim 10, wherein at least any one of encryptionkey information, encryption key production information, contentsreproduction control information, and contents copying controlinformation for contents to be stored in the information recordingmedium is produced based on the acquired additional data constituent bitinformation.
 15. An information recording medium for storing thereinrecord data based on a recording frame set with a DC control bitaccording to DSV control; and record data based on a recording frameassociated to additional data with a bit value specified based onconstituent bit information of additional data set on a plurality of DCcontrol bit positions.
 16. The information recording medium according toclaim 15, wherein bit information stored at a plurality of DC controlbit position based on information associated to additional data in theadditional data-associated recording frame is different from bitinformation based on DSV measurement.
 17. The information recordingmedium according to claim 15, wherein bit information associated toadditional data set in one additional data-associated recording frameindicates a signal constituent bit of 0 or 1 in the additional data. 18.The information recording medium according to claim 15, wherein bitinformation associated to additional data set in one additionaldata-associated recording frame indicates a plurality of constituentbits in the additional data.
 19. The information recording mediumaccording to claim 15, wherein the additional data is stored as at leastone of encryption key information, encryption key productioninformation, contents reproduction control information, and contentscopying control information for contents to be stored in the informationrecording medium.
 20. The information recording medium according toclaim 15, wherein data based on a modulated recording frame produced byexecuting data conversion satisfying RLL (1, 7) as the run lengthlimited is recorded therein.
 21. The information recording mediumaccording to claim 15, wherein data based on a modulated recording frameproduced by executing conversion of 2-bit information to 3-bitinformation is recorded therein.
 22. A method of information recordprocessing comprising the step of: specifying a DC control bit forspecifying a bit value to be set at an additional data-associated DCcontrol bit position selected from a plurality of additionaldata-associated DC control bit setting positions included in anadditional data-associated recording frame based on a constituent bitinformation of the additional data; and producing modulated recordingframe as a record unit by setting the bit value specified in said DCcontrol bit specifying step at said additional data-associated DCcontrol bit position in the additional data-associated recording frameand executing data modulation.
 23. The method of information recordprocessing according to claim 22, wherein the DC control bit specifyingsection sets a plurality of DC control bit positions included in theadditional data-associated recording frame as additional data-associatedDC control bit positions and decides a plurality of bit values at theadditional data-associated DC control bit positions based on constituentbit information of the additional data.
 24. The method of informationrecord processing according to claim 22, wherein the DC control bitspecifying step comprises the steps of: deciding one bit informationselected from a plurality of different DC control bit informationassociated to one constituent bit information of the additional data asbit information to be set at an additional data-associated DC controlbit position; and deciding, when bit information based on DSVmeasurement at the additional data-associated DC control bit position isidentical to the DC control bit information corresponding to theadditional data constituent bit information to be set, bit informationdifferent from the bit information based on DSV measurement as bitinformation to be set at the additional data-associated DC control bitposition.
 25. The method of information record processing according toclaim 22, wherein the DC control bit specifying step comprises the stepsof: deciding one bit information selected from a plurality of differentDC control bit information associated to one constituent bit informationof the additional data as bit information to be set at an additionaldata-associated DC control bit position; and deciding bit informationrequiring minimum change of bits from the bit information based on DSVmeasurement at the additional data-associated DC control bit informationas bit information to be set at the additional data-associated DCcontrol bit position.
 26. The method of information record processingaccording to claim 22, wherein the DC control bit specifying stepcomprises the step of deciding different bit information as bitinformation to be set at the additional data-associated DC control bitposition according to a single constituent bit of 0 or 1 of theadditional data.
 27. The method of information record processingaccording to claim 22, wherein the DC control bit specifying stepcomprises the step of deciding different bit information as bitinformation to be set at the additional data-associated DC control bitposition according to a plurality of additional data constituent bitarrays.
 28. The method of information record processing according toclaim 22 further comprising the step of setting the additional data asat least any of encryption key information, encryption key productioninformation, contents reproduction control information, and contentscopying control information for contents to be stored in the informationrecording medium.
 29. The information recording method according toclaim 22, wherein, in the modulated data producing step, a modulatedrecording frame is produced by executing data conversion satisfying RLL(1, 7) as the run length limited.
 30. The information recording methodaccording claim 22, wherein the modulated data producing step comprisesthe step of converting 2-bit information to 3-bit information.
 31. Amethod of reproducing information stored in an information recordingmedium comprising the steps of: modulating data read from an informationrecording medium; and decoding an additional data by analyzing bitinformation set at an additional data-associated DC control bit positionincluded in a recording frame associated to additional data andacquiring additional data constituent bit information based a result ofthe analysis.
 32. The information reproducing method according to claim31, wherein the additional data decoding step comprises the step ofanalyzing a plurality of DC control bits included in the additionaldata-associated recording frame and acquiring bit information previouslyassociated to a bit array to be acquired as additional data constituentbit information according to a result of analysis.
 33. The informationreproducing method according to claim 31, wherein, in the additionaldata decoding step, a single constituent bit of [0] or [1] of theadditional data is acquired based on the bit information set atdata-associated DC control bit position set in one recording frame. 34.The information reproducing method according to claim 31, wherein, inthe additional data decoding step, the plurality of constituent bitinformation of the additional data is acquired based on the bitinformation set at the additional data-associated DC control bitpositions set in one recording frame.
 35. The information reproducingmethod according to claim 31 further comprising the step of producing atleast any one of encryption key information, encryption key productioninformation, contents reproduction control information, and contentscopying control information for contents to be stored in the informationrecording medium based on the acquired additional data constituent bitinformation.
 36. A computer program for executing information recordprocessing, comprising the steps of: specifying a DC control bit forspecifying a bit value to be set at an additional data-associated DCcontrol bit position selected from a plurality of additionaldata-associated DC control bit setting positions included in anadditional data-associated recording frame based on a constituent bitinformation of the additional data; and producing modulated recordingframe as a record unit by setting the bit value specified in said DCcontrol bit specifying step at said additional data-associated DCcontrol bit position in the additional data-associated recording frameand executing data modulation.
 37. A computer program for reproducinginformation stored in an information recording medium, said programcomprising the steps of: modulating data read out from an informationrecording medium; and decoding an additional data by analyzing bitinformation set at an additional data-associated DC control bit positionincluded in an additional data-associated recording frame and acquiringadditional data constituent bit information according to a result of theanalysis.